I'm guessing that Kenshalans are a custom race; don't think I've ever heard of them.
If you're using d20s, though, you're apt to have a HUGE difference between the tallest and the shortest of the race. It's as easy to roll a 1 as it is a 20, whereas with systems like 2d10, you're more apt to roll an 11 than anything else, with various extremes being less common.
If you need a huge number like 3d20, you're going to somewhat gravitate towards 31.5, but not nearly as much as if you used 6d10, for example.
I would ask: do you actually want there to be this gigantic variance? What's the average that you'd want to have, and what would be the extremes of this number?
If I remember correctly, for 3rd edition D&D, you end up multiplying the extra inches of height to another roll to determine weight. I may be wrong on this, though.